The present invention relates to the general field of cooling moving blades for turbomachines, and in particular the blades of a high pressure turbine.
In a turbomachine, it is known to provide the moving blades of a gas turbine, such as the high pressure turbine or the low pressure turbine, with internal cooling circuits enabling them to withstand without damage the very high temperatures to which they are subjected while the turbomachine is in operation. Thus, in a high pressure turbine, the temperature of the gas coming from the combustion chamber can reach values that are well above those that can be withstood by the moving blades of the turbine without damage, thereby having the consequence of reducing their lifetime.
By means of such cooling circuits, air which is generally introduced into the blade via its root, travels through the blade following a path made up of cavities formed inside the blade, prior to being ejected through orifices that open out in the surface of the blade.
A wide variety of different configurations exist for such cooling circuits. Thus, certain circuits make use of cooling cavities that occupy the entire width of the blade, thereby presenting the drawback of limiting the thermal efficiency of the cooling. In order to mitigate that defect, other circuits, such as those described in patent documents EP 1 288 438 and EP 1 288 439, propose using edge cooling cavities occupying only one side of the blade (pressure side or suction side), or both sides with the addition of a large central cavity between the edge cavities. Although such circuits are effective from a thermal point of view, they remain difficult and expensive to produce by casting and the weight of the resulting blade is large.